less.man revision 170256
1161475SdelphijLESS(1) LESS(1) 260786Sps 360786Sps 460786Sps 5170256Sdelphij[1mNAME[0m 660786Sps less - opposite of more 760786Sps 8170256Sdelphij[1mSYNOPSIS[0m 9170256Sdelphij [1mless -?[0m 10170256Sdelphij [1mless --help[0m 11170256Sdelphij [1mless -V[0m 12170256Sdelphij [1mless --version[0m 13170256Sdelphij [1mless [-[+]aBcCdeEfFgGiIJKLmMnNqQrRsSuUVwWX~][0m 14170256Sdelphij [1m[-b [4m[22mspace[24m[1m] [-h [4m[22mlines[24m[1m] [-j [4m[22mline[24m[1m] [-k [4m[22mkeyfile[24m[1m][0m 15170256Sdelphij [1m[-{oO} [4m[22mlogfile[24m[1m] [-p [4m[22mpattern[24m[1m] [-P [4m[22mprompt[24m[1m] [-t [4m[22mtag[24m[1m][0m 16170256Sdelphij [1m[-T [4m[22mtagsfile[24m[1m] [-x [4m[22mtab[24m[1m,...] [-y [4m[22mlines[24m[1m] [-[z] [4m[22mlines[24m[1m][0m 17170256Sdelphij [1m[-# [4m[22mshift[24m[1m] [+[+][4m[22mcmd[24m[1m] [--] [[4m[22mfilename[24m[1m]...[0m 18161475Sdelphij (See the OPTIONS section for alternate option syntax with long option 19161475Sdelphij names.) 2060786Sps 2160786Sps 22170256Sdelphij[1mDESCRIPTION[0m 23170256Sdelphij [4mLess[24m is a program similar to [4mmore[24m (1), but which allows backward move- 24170256Sdelphij ment in the file as well as forward movement. Also, [4mless[24m does not have 25161475Sdelphij to read the entire input file before starting, so with large input 26170256Sdelphij files it starts up faster than text editors like [4mvi[24m (1). [4mLess[24m uses 27161475Sdelphij termcap (or terminfo on some systems), so it can run on a variety of 28161475Sdelphij terminals. There is even limited support for hardcopy terminals. (On 29161475Sdelphij a hardcopy terminal, lines which should be printed at the top of the 30161475Sdelphij screen are prefixed with a caret.) 3160786Sps 32170256Sdelphij Commands are based on both [4mmore[24m and [4mvi.[24m Commands may be preceded by a 33161475Sdelphij decimal number, called N in the descriptions below. The number is used 34161475Sdelphij by some commands, as indicated. 3560786Sps 3660786Sps 37170256Sdelphij[1mCOMMANDS[0m 38161475Sdelphij In the following descriptions, ^X means control-X. ESC stands for the 39161475Sdelphij ESCAPE key; for example ESC-v means the two character sequence 40161475Sdelphij "ESCAPE", then "v". 4160786Sps 42161475Sdelphij h or H Help: display a summary of these commands. If you forget all 43161475Sdelphij the other commands, remember this one. 4460786Sps 4560786Sps SPACE or ^V or f or ^F 46161475Sdelphij Scroll forward N lines, default one window (see option -z 47161475Sdelphij below). If N is more than the screen size, only the final 48161475Sdelphij screenful is displayed. Warning: some systems use ^V as a spe- 49161475Sdelphij cial literalization character. 5060786Sps 51161475Sdelphij z Like SPACE, but if N is specified, it becomes the new window 52161475Sdelphij size. 5360786Sps 5460786Sps ESC-SPACE 55161475Sdelphij Like SPACE, but scrolls a full screenful, even if it reaches 56161475Sdelphij end-of-file in the process. 5760786Sps 5860786Sps RETURN or ^N or e or ^E or j or ^J 59161475Sdelphij Scroll forward N lines, default 1. The entire N lines are dis- 60161475Sdelphij played, even if N is more than the screen size. 6160786Sps 6260786Sps d or ^D 63161475Sdelphij Scroll forward N lines, default one half of the screen size. If 64161475Sdelphij N is specified, it becomes the new default for subsequent d and 65161475Sdelphij u commands. 6660786Sps 6760786Sps b or ^B or ESC-v 68161475Sdelphij Scroll backward N lines, default one window (see option -z 69161475Sdelphij below). If N is more than the screen size, only the final 70161475Sdelphij screenful is displayed. 7160786Sps 72161475Sdelphij w Like ESC-v, but if N is specified, it becomes the new window 73161475Sdelphij size. 7460786Sps 7560786Sps y or ^Y or ^P or k or ^K 76161475Sdelphij Scroll backward N lines, default 1. The entire N lines are dis- 77161475Sdelphij played, even if N is more than the screen size. Warning: some 78161475Sdelphij systems use ^Y as a special job control character. 7960786Sps 8060786Sps u or ^U 81161475Sdelphij Scroll backward N lines, default one half of the screen size. 82161475Sdelphij If N is specified, it becomes the new default for subsequent d 83161475Sdelphij and u commands. 8460786Sps 8560786Sps ESC-) or RIGHTARROW 86161475Sdelphij Scroll horizontally right N characters, default half the screen 87161475Sdelphij width (see the -# option). If a number N is specified, it 88161475Sdelphij becomes the default for future RIGHTARROW and LEFTARROW com- 89161475Sdelphij mands. While the text is scrolled, it acts as though the -S 9089019Sps option (chop lines) were in effect. 9160786Sps 9260786Sps ESC-( or LEFTARROW 93161475Sdelphij Scroll horizontally left N characters, default half the screen 94161475Sdelphij width (see the -# option). If a number N is specified, it 95161475Sdelphij becomes the default for future RIGHTARROW and LEFTARROW com- 96161475Sdelphij mands. 9760786Sps 9860786Sps r or ^R or ^L 9960786Sps Repaint the screen. 10060786Sps 101161475Sdelphij R Repaint the screen, discarding any buffered input. Useful if 102161475Sdelphij the file is changing while it is being viewed. 10360786Sps 104161475Sdelphij F Scroll forward, and keep trying to read when the end of file is 105161475Sdelphij reached. Normally this command would be used when already at 106161475Sdelphij the end of the file. It is a way to monitor the tail of a file 107161475Sdelphij which is growing while it is being viewed. (The behavior is 10860786Sps similar to the "tail -f" command.) 10960786Sps 11060786Sps g or < or ESC-< 111161475Sdelphij Go to line N in the file, default 1 (beginning of file). (Warn- 112161475Sdelphij ing: this may be slow if N is large.) 11360786Sps 11460786Sps G or > or ESC-> 115161475Sdelphij Go to line N in the file, default the end of the file. (Warn- 116161475Sdelphij ing: this may be slow if N is large, or if N is not specified 117161475Sdelphij and standard input, rather than a file, is being read.) 11860786Sps 119161475Sdelphij p or % Go to a position N percent into the file. N should be between 0 120170256Sdelphij and 100, and may contain a decimal point. 12160786Sps 122170256Sdelphij P Go to the line containing byte offset N in the file. 123170256Sdelphij 124161475Sdelphij { If a left curly bracket appears in the top line displayed on the 125161475Sdelphij screen, the { command will go to the matching right curly 126161475Sdelphij bracket. The matching right curly bracket is positioned on the 127161475Sdelphij bottom line of the screen. If there is more than one left curly 128161475Sdelphij bracket on the top line, a number N may be used to specify the 129161475Sdelphij N-th bracket on the line. 13060786Sps 131161475Sdelphij } If a right curly bracket appears in the bottom line displayed on 132161475Sdelphij the screen, the } command will go to the matching left curly 133161475Sdelphij bracket. The matching left curly bracket is positioned on the 134161475Sdelphij top line of the screen. If there is more than one right curly 135161475Sdelphij bracket on the top line, a number N may be used to specify the 136161475Sdelphij N-th bracket on the line. 13760786Sps 138161475Sdelphij ( Like {, but applies to parentheses rather than curly brackets. 13960786Sps 140161475Sdelphij ) Like }, but applies to parentheses rather than curly brackets. 14160786Sps 142161475Sdelphij [ Like {, but applies to square brackets rather than curly brack- 143161475Sdelphij ets. 14460786Sps 145161475Sdelphij ] Like }, but applies to square brackets rather than curly brack- 146161475Sdelphij ets. 14760786Sps 148161475Sdelphij ESC-^F Followed by two characters, acts like {, but uses the two char- 149161475Sdelphij acters as open and close brackets, respectively. For example, 150161475Sdelphij "ESC ^F < >" could be used to go forward to the > which matches 151161475Sdelphij the < in the top displayed line. 15260786Sps 153161475Sdelphij ESC-^B Followed by two characters, acts like }, but uses the two char- 154161475Sdelphij acters as open and close brackets, respectively. For example, 155161475Sdelphij "ESC ^B < >" could be used to go backward to the < which matches 156161475Sdelphij the > in the bottom displayed line. 15760786Sps 158161475Sdelphij m Followed by any lowercase letter, marks the current position 159161475Sdelphij with that letter. 16060786Sps 161161475Sdelphij ' (Single quote.) Followed by any lowercase letter, returns to 162161475Sdelphij the position which was previously marked with that letter. Fol- 163161475Sdelphij lowed by another single quote, returns to the position at which 164161475Sdelphij the last "large" movement command was executed. Followed by a ^ 165161475Sdelphij or $, jumps to the beginning or end of the file respectively. 166161475Sdelphij Marks are preserved when a new file is examined, so the ' com- 167161475Sdelphij mand can be used to switch between input files. 16860786Sps 16960786Sps ^X^X Same as single quote. 17060786Sps 17160786Sps /pattern 172161475Sdelphij Search forward in the file for the N-th line containing the pat- 173161475Sdelphij tern. N defaults to 1. The pattern is a regular expression, as 174161475Sdelphij recognized by the regular expression library supplied by your 175161475Sdelphij system. The search starts at the second line displayed (but see 17660786Sps the -a and -j options, which change this). 17760786Sps 178161475Sdelphij Certain characters are special if entered at the beginning of 179161475Sdelphij the pattern; they modify the type of search rather than become 180161475Sdelphij part of the pattern: 18160786Sps 18260786Sps ^N or ! 183161475Sdelphij Search for lines which do NOT match the pattern. 18460786Sps 18560786Sps ^E or * 186161475Sdelphij Search multiple files. That is, if the search reaches 187161475Sdelphij the END of the current file without finding a match, the 188161475Sdelphij search continues in the next file in the command line 18960786Sps list. 19060786Sps 19160786Sps ^F or @ 192161475Sdelphij Begin the search at the first line of the FIRST file in 193161475Sdelphij the command line list, regardless of what is currently 194161475Sdelphij displayed on the screen or the settings of the -a or -j 19560786Sps options. 19660786Sps 197161475Sdelphij ^K Highlight any text which matches the pattern on the cur- 198170256Sdelphij rent screen, but don't move to the first match (KEEP 199170256Sdelphij current position). 20060786Sps 201161475Sdelphij ^R Don't interpret regular expression metacharacters; that 202161475Sdelphij is, do a simple textual comparison. 20360786Sps 20463128Sps ?pattern 205161475Sdelphij Search backward in the file for the N-th line containing the 206161475Sdelphij pattern. The search starts at the line immediately before the 207161475Sdelphij top line displayed. 20863128Sps 20960786Sps Certain characters are special as in the / command: 21060786Sps 21160786Sps ^N or ! 212161475Sdelphij Search for lines which do NOT match the pattern. 21360786Sps 21460786Sps ^E or * 215161475Sdelphij Search multiple files. That is, if the search reaches 216161475Sdelphij the beginning of the current file without finding a 217161475Sdelphij match, the search continues in the previous file in the 218161475Sdelphij command line list. 21960786Sps 22060786Sps ^F or @ 221161475Sdelphij Begin the search at the last line of the last file in the 222161475Sdelphij command line list, regardless of what is currently dis- 223161475Sdelphij played on the screen or the settings of the -a or -j 22460786Sps options. 22560786Sps 22660786Sps ^K As in forward searches. 22760786Sps 22860786Sps ^R As in forward searches. 22960786Sps 23060786Sps ESC-/pattern 23160786Sps Same as "/*". 23260786Sps 23360786Sps ESC-?pattern 23460786Sps Same as "?*". 23560786Sps 236161475Sdelphij n Repeat previous search, for N-th line containing the last pat- 237161475Sdelphij tern. If the previous search was modified by ^N, the search is 238161475Sdelphij made for the N-th line NOT containing the pattern. If the pre- 239161475Sdelphij vious search was modified by ^E, the search continues in the 240161475Sdelphij next (or previous) file if not satisfied in the current file. 241161475Sdelphij If the previous search was modified by ^R, the search is done 242161475Sdelphij without using regular expressions. There is no effect if the 243161475Sdelphij previous search was modified by ^F or ^K. 24460786Sps 245161475Sdelphij N Repeat previous search, but in the reverse direction. 24660786Sps 247161475Sdelphij ESC-n Repeat previous search, but crossing file boundaries. The 248161475Sdelphij effect is as if the previous search were modified by *. 24960786Sps 250161475Sdelphij ESC-N Repeat previous search, but in the reverse direction and cross- 251161475Sdelphij ing file boundaries. 25260786Sps 253161475Sdelphij ESC-u Undo search highlighting. Turn off highlighting of strings 254161475Sdelphij matching the current search pattern. If highlighting is already 255161475Sdelphij off because of a previous ESC-u command, turn highlighting back 256161475Sdelphij on. Any search command will also turn highlighting back on. 257161475Sdelphij (Highlighting can also be disabled by toggling the -G option; in 258161475Sdelphij that case search commands do not turn highlighting back on.) 25960786Sps 26060786Sps :e [filename] 261161475Sdelphij Examine a new file. If the filename is missing, the "current" 262161475Sdelphij file (see the :n and :p commands below) from the list of files 263161475Sdelphij in the command line is re-examined. A percent sign (%) in the 264161475Sdelphij filename is replaced by the name of the current file. A pound 265161475Sdelphij sign (#) is replaced by the name of the previously examined 266161475Sdelphij file. However, two consecutive percent signs are simply 267161475Sdelphij replaced with a single percent sign. This allows you to enter a 268161475Sdelphij filename that contains a percent sign in the name. Similarly, 269161475Sdelphij two consecutive pound signs are replaced with a single pound 270161475Sdelphij sign. The filename is inserted into the command line list of 271161475Sdelphij files so that it can be seen by subsequent :n and :p commands. 272161475Sdelphij If the filename consists of several files, they are all inserted 273161475Sdelphij into the list of files and the first one is examined. If the 274161475Sdelphij filename contains one or more spaces, the entire filename should 275161475Sdelphij be enclosed in double quotes (also see the -" option). 27660786Sps 27760786Sps ^X^V or E 278161475Sdelphij Same as :e. Warning: some systems use ^V as a special literal- 279161475Sdelphij ization character. On such systems, you may not be able to use 280161475Sdelphij ^V. 28160786Sps 282161475Sdelphij :n Examine the next file (from the list of files given in the com- 283161475Sdelphij mand line). If a number N is specified, the N-th next file is 284161475Sdelphij examined. 28560786Sps 286161475Sdelphij :p Examine the previous file in the command line list. If a number 287161475Sdelphij N is specified, the N-th previous file is examined. 28860786Sps 289161475Sdelphij :x Examine the first file in the command line list. If a number N 290161475Sdelphij is specified, the N-th file in the list is examined. 29160786Sps 29260786Sps :d Remove the current file from the list of files. 29360786Sps 294161475Sdelphij t Go to the next tag, if there were more than one matches for the 295161475Sdelphij current tag. See the -t option for more details about tags. 29660786Sps 297161475Sdelphij T Go to the previous tag, if there were more than one matches for 298161475Sdelphij the current tag. 29960786Sps 30089019Sps = or ^G or :f 301161475Sdelphij Prints some information about the file being viewed, including 302161475Sdelphij its name and the line number and byte offset of the bottom line 303161475Sdelphij being displayed. If possible, it also prints the length of the 304161475Sdelphij file, the number of lines in the file and the percent of the 305161475Sdelphij file above the last displayed line. 30660786Sps 307161475Sdelphij - Followed by one of the command line option letters (see OPTIONS 308161475Sdelphij below), this will change the setting of that option and print a 309161475Sdelphij message describing the new setting. If a ^P (CONTROL-P) is 310161475Sdelphij entered immediately after the dash, the setting of the option is 311161475Sdelphij changed but no message is printed. If the option letter has a 312161475Sdelphij numeric value (such as -b or -h), or a string value (such as -P 313161475Sdelphij or -t), a new value may be entered after the option letter. If 314161475Sdelphij no new value is entered, a message describing the current set- 315161475Sdelphij ting is printed and nothing is changed. 31660786Sps 317161475Sdelphij -- Like the - command, but takes a long option name (see OPTIONS 318161475Sdelphij below) rather than a single option letter. You must press 319161475Sdelphij RETURN after typing the option name. A ^P immediately after the 320161475Sdelphij second dash suppresses printing of a message describing the new 321161475Sdelphij setting, as in the - command. 32260786Sps 323161475Sdelphij -+ Followed by one of the command line option letters this will 324161475Sdelphij reset the option to its default setting and print a message 325170256Sdelphij describing the new setting. (The "-+[4mX[24m" command does the same 326170256Sdelphij thing as "-+[4mX[24m" on the command line.) This does not work for 32760786Sps string-valued options. 32860786Sps 329161475Sdelphij --+ Like the -+ command, but takes a long option name rather than a 330161475Sdelphij single option letter. 33160786Sps 332161475Sdelphij -! Followed by one of the command line option letters, this will 333161475Sdelphij reset the option to the "opposite" of its default setting and 334161475Sdelphij print a message describing the new setting. This does not work 335161475Sdelphij for numeric or string-valued options. 33660786Sps 337161475Sdelphij --! Like the -! command, but takes a long option name rather than a 338161475Sdelphij single option letter. 33960786Sps 340161475Sdelphij _ (Underscore.) Followed by one of the command line option let- 341161475Sdelphij ters, this will print a message describing the current setting 342161475Sdelphij of that option. The setting of the option is not changed. 34360786Sps 344161475Sdelphij __ (Double underscore.) Like the _ (underscore) command, but takes 345161475Sdelphij a long option name rather than a single option letter. You must 346161475Sdelphij press RETURN after typing the option name. 34760786Sps 348161475Sdelphij +cmd Causes the specified cmd to be executed each time a new file is 349170256Sdelphij examined. For example, +G causes [4mless[24m to initially display each 350161475Sdelphij file starting at the end rather than the beginning. 35160786Sps 352170256Sdelphij V Prints the version number of [4mless[24m being run. 35360786Sps 35460786Sps q or Q or :q or :Q or ZZ 355170256Sdelphij Exits [4mless.[0m 35660786Sps 357161475Sdelphij The following four commands may or may not be valid, depending on your 358161475Sdelphij particular installation. 35960786Sps 36060786Sps 361161475Sdelphij v Invokes an editor to edit the current file being viewed. The 362161475Sdelphij editor is taken from the environment variable VISUAL if defined, 363161475Sdelphij or EDITOR if VISUAL is not defined, or defaults to "vi" if nei- 364161475Sdelphij ther VISUAL nor EDITOR is defined. See also the discussion of 36560786Sps LESSEDIT under the section on PROMPTS below. 36660786Sps 36760786Sps ! shell-command 368161475Sdelphij Invokes a shell to run the shell-command given. A percent sign 369161475Sdelphij (%) in the command is replaced by the name of the current file. 370161475Sdelphij A pound sign (#) is replaced by the name of the previously exam- 371161475Sdelphij ined file. "!!" repeats the last shell command. "!" with no 372161475Sdelphij shell command simply invokes a shell. On Unix systems, the 373161475Sdelphij shell is taken from the environment variable SHELL, or defaults 374161475Sdelphij to "sh". On MS-DOS and OS/2 systems, the shell is the normal 375161475Sdelphij command processor. 37660786Sps 37760786Sps | <m> shell-command 378161475Sdelphij <m> represents any mark letter. Pipes a section of the input 379161475Sdelphij file to the given shell command. The section of the file to be 380161475Sdelphij piped is between the first line on the current screen and the 381161475Sdelphij position marked by the letter. <m> may also be ^ or $ to indi- 382161475Sdelphij cate beginning or end of file respectively. If <m> is . or new- 383161475Sdelphij line, the current screen is piped. 38460786Sps 38560786Sps s filename 386161475Sdelphij Save the input to a file. This only works if the input is a 387161475Sdelphij pipe, not an ordinary file. 38860786Sps 38960786Sps 390170256Sdelphij[1mOPTIONS[0m 391161475Sdelphij Command line options are described below. Most options may be changed 392170256Sdelphij while [4mless[24m is running, via the "-" command. 39389019Sps 394161475Sdelphij Most options may be given in one of two forms: either a dash followed 395161475Sdelphij by a single letter, or two dashes followed by a long option name. A 396161475Sdelphij long option name may be abbreviated as long as the abbreviation is 397161475Sdelphij unambiguous. For example, --quit-at-eof may be abbreviated --quit, but 398161475Sdelphij not --qui, since both --quit-at-eof and --quiet begin with --qui. Some 399161475Sdelphij long option names are in uppercase, such as --QUIT-AT-EOF, as distinct 400170256Sdelphij from --quit-at-eof. Such option names need only have their first let- 401170256Sdelphij ter capitalized; the remainder of the name may be in either case. For 402170256Sdelphij example, --Quit-at-eof is equivalent to --QUIT-AT-EOF. 40360786Sps 404161475Sdelphij Options are also taken from the environment variable "LESS". For exam- 405170256Sdelphij ple, to avoid typing "less -options ..." each time [4mless[24m is invoked, you 406170256Sdelphij might tell [4mcsh:[0m 40760786Sps 40860786Sps setenv LESS "-options" 40960786Sps 410170256Sdelphij or if you use [4msh:[0m 41160786Sps 41260786Sps LESS="-options"; export LESS 41360786Sps 414161475Sdelphij On MS-DOS, you don't need the quotes, but you should replace any per- 415161475Sdelphij cent signs in the options string by double percent signs. 41660786Sps 417161475Sdelphij The environment variable is parsed before the command line, so command 418161475Sdelphij line options override the LESS environment variable. If an option 419161475Sdelphij appears in the LESS variable, it can be reset to its default value on 420161475Sdelphij the command line by beginning the command line option with "-+". 42160786Sps 422161475Sdelphij For options like -P or -D which take a following string, a dollar sign 423161475Sdelphij ($) must be used to signal the end of the string. For example, to set 424161475Sdelphij two -D options on MS-DOS, you must have a dollar sign between them, 425161475Sdelphij like this: 42660786Sps 42760786Sps LESS="-Dn9.1$-Ds4.1" 42860786Sps 42960786Sps 43060786Sps -? or --help 431170256Sdelphij This option displays a summary of the commands accepted by [4mless[0m 432161475Sdelphij (the same as the h command). (Depending on how your shell 433161475Sdelphij interprets the question mark, it may be necessary to quote the 434161475Sdelphij question mark, thus: "-\?".) 43560786Sps 43660786Sps -a or --search-skip-screen 437161475Sdelphij Causes searches to start after the last line displayed on the 438161475Sdelphij screen, thus skipping all lines displayed on the screen. By 439161475Sdelphij default, searches start at the second line on the screen (or 440161475Sdelphij after the last found line; see the -j option). 44160786Sps 442170256Sdelphij -b[4mn[24m or --buffers=[4mn[0m 443170256Sdelphij Specifies the amount of buffer space [4mless[24m will use for each 444161475Sdelphij file, in units of kilobytes (1024 bytes). By default 64K of 445161475Sdelphij buffer space is used for each file (unless the file is a pipe; 446170256Sdelphij see the -B option). The -b option specifies instead that [4mn[0m 447170256Sdelphij kilobytes of buffer space should be used for each file. If [4mn[24m is 448161475Sdelphij -1, buffer space is unlimited; that is, the entire file is read 449161475Sdelphij into memory. 45063128Sps 45160786Sps -B or --auto-buffers 452161475Sdelphij By default, when data is read from a pipe, buffers are allocated 453161475Sdelphij automatically as needed. If a large amount of data is read from 454161475Sdelphij the pipe, this can cause a large amount of memory to be allo- 455161475Sdelphij cated. The -B option disables this automatic allocation of 456161475Sdelphij buffers for pipes, so that only 64K (or the amount of space 457161475Sdelphij specified by the -b option) is used for the pipe. Warning: use 458161475Sdelphij of -B can result in erroneous display, since only the most 459161475Sdelphij recently viewed part of the file is kept in memory; any earlier 460128345Stjr data is lost. 46160786Sps 46260786Sps -c or --clear-screen 463161475Sdelphij Causes full screen repaints to be painted from the top line 464161475Sdelphij down. By default, full screen repaints are done by scrolling 465161475Sdelphij from the bottom of the screen. 46660786Sps 46760786Sps -C or --CLEAR-SCREEN 468170256Sdelphij Same as -c, for compatibility with older versions of [4mless.[0m 46960786Sps 47060786Sps -d or --dumb 471161475Sdelphij The -d option suppresses the error message normally displayed if 472170256Sdelphij the terminal is dumb; that is, lacks some important capability, 473161475Sdelphij such as the ability to clear the screen or scroll backward. The 474170256Sdelphij -d option does not otherwise change the behavior of [4mless[24m on a 475128345Stjr dumb terminal. 47660786Sps 477170256Sdelphij -D[1mx[4m[22mcolor[24m or --color=[1mx[4m[22mcolor[0m 478170256Sdelphij [MS-DOS only] Sets the color of the text displayed. [1mx [22mis a sin- 479170256Sdelphij gle character which selects the type of text whose color is 480170256Sdelphij being set: n=normal, s=standout, d=bold, u=underlined, k=blink. 481170256Sdelphij [4mcolor[24m is a pair of numbers separated by a period. The first 482170256Sdelphij number selects the foreground color and the second selects the 483170256Sdelphij background color of the text. A single number [4mN[24m is the same as 484170256Sdelphij [4mN.0[24m. 48560786Sps 486128345Stjr -e or --quit-at-eof 487170256Sdelphij Causes [4mless[24m to automatically exit the second time it reaches 488170256Sdelphij end-of-file. By default, the only way to exit [4mless[24m is via the 489161475Sdelphij "q" command. 49063128Sps 49189019Sps -E or --QUIT-AT-EOF 492170256Sdelphij Causes [4mless[24m to automatically exit the first time it reaches end- 493161475Sdelphij of-file. 49460786Sps 49563128Sps -f or --force 496161475Sdelphij Forces non-regular files to be opened. (A non-regular file is a 497170256Sdelphij directory or a device special file.) Also suppresses the warn- 498170256Sdelphij ing message when a binary file is opened. By default, [4mless[24m will 499170256Sdelphij refuse to open non-regular files. Note that some operating sys- 500170256Sdelphij tems will not allow directories to be read, even if -f is set. 50160786Sps 50260786Sps -F or --quit-if-one-screen 503170256Sdelphij Causes [4mless[24m to automatically exit if the entire file can be dis- 504161475Sdelphij played on the first screen. 50560786Sps 50660786Sps -g or --hilite-search 507170256Sdelphij Normally, [4mless[24m will highlight ALL strings which match the last 508161475Sdelphij search command. The -g option changes this behavior to high- 509161475Sdelphij light only the particular string which was found by the last 510170256Sdelphij search command. This can cause [4mless[24m to run somewhat faster than 511161475Sdelphij the default. 51260786Sps 51360786Sps -G or --HILITE-SEARCH 514161475Sdelphij The -G option suppresses all highlighting of strings found by 515161475Sdelphij search commands. 51660786Sps 517170256Sdelphij -h[4mn[24m or --max-back-scroll=[4mn[0m 518161475Sdelphij Specifies a maximum number of lines to scroll backward. If it 519170256Sdelphij is necessary to scroll backward more than [4mn[24m lines, the screen is 520161475Sdelphij repainted in a forward direction instead. (If the terminal does 521161475Sdelphij not have the ability to scroll backward, -h0 is implied.) 52260786Sps 52360786Sps -i or --ignore-case 524161475Sdelphij Causes searches to ignore case; that is, uppercase and lowercase 525161475Sdelphij are considered identical. This option is ignored if any upper- 526161475Sdelphij case letters appear in the search pattern; in other words, if a 527161475Sdelphij pattern contains uppercase letters, then that search does not 528161475Sdelphij ignore case. 52960786Sps 53060786Sps -I or --IGNORE-CASE 531161475Sdelphij Like -i, but searches ignore case even if the pattern contains 532161475Sdelphij uppercase letters. 53360786Sps 534170256Sdelphij -j[4mn[24m or --jump-target=[4mn[0m 535161475Sdelphij Specifies a line on the screen where the "target" line is to be 536161475Sdelphij positioned. A target line is the object of a text search, tag 537161475Sdelphij search, jump to a line number, jump to a file percentage, or 538170256Sdelphij jump to a marked position. The screen line may be specified by 539170256Sdelphij a number: the top line on the screen is 1, the next is 2, and so 540161475Sdelphij on. The number may be negative to specify a line relative to 541161475Sdelphij the bottom of the screen: the bottom line on the screen is -1, 542170256Sdelphij the second to the bottom is -2, and so on. Alternately, the 543170256Sdelphij screen line may be specified as a fraction of the height of the 544170256Sdelphij screen, starting with a decimal point: .5 is in the middle of 545170256Sdelphij the screen, .3 is three tenths down from the first line, and so 546170256Sdelphij on. If the line is specified as a fraction, the actual line 547170256Sdelphij number is recalculated if the terminal window is resized, so 548170256Sdelphij that the target line remains at the specified fraction of the 549170256Sdelphij screen height. If the -j option is used, searches begin at the 550170256Sdelphij line immediately after the target line. For example, if "-j4" 551170256Sdelphij is used, the target line is the fourth line on the screen, so 552170256Sdelphij searches begin at the fifth line on the screen. 55360786Sps 55463128Sps -J or --status-column 555161475Sdelphij Displays a status column at the left edge of the screen. The 556161475Sdelphij status column shows the lines that matched the current search. 557161475Sdelphij The status column is also used if the -w or -W option is in 558161475Sdelphij effect. 55963128Sps 560170256Sdelphij -k[4mfilename[24m or --lesskey-file=[4mfilename[0m 561170256Sdelphij Causes [4mless[24m to open and interpret the named file as a [4mlesskey[0m 562161475Sdelphij (1) file. Multiple -k options may be specified. If the LESSKEY 563161475Sdelphij or LESSKEY_SYSTEM environment variable is set, or if a lesskey 564161475Sdelphij file is found in a standard place (see KEY BINDINGS), it is also 565170256Sdelphij used as a [4mlesskey[24m file. 56660786Sps 567161475Sdelphij -K or --quit-on-intr 568170256Sdelphij Causes [4mless[24m to exit immediately when an interrupt character 569161475Sdelphij (usually ^C) is typed. Normally, an interrupt character causes 570170256Sdelphij [4mless[24m to stop whatever it is doing and return to its command 571161475Sdelphij prompt. 572161475Sdelphij 573128345Stjr -L or --no-lessopen 574161475Sdelphij Ignore the LESSOPEN environment variable (see the INPUT PREPRO- 575170256Sdelphij CESSOR section below). This option can be set from within [4mless[24m, 576161475Sdelphij but it will apply only to files opened subsequently, not to the 577161475Sdelphij file which is currently open. 578128345Stjr 57960786Sps -m or --long-prompt 580170256Sdelphij Causes [4mless[24m to prompt verbosely (like [4mmore[24m), with the percent 581170256Sdelphij into the file. By default, [4mless[24m prompts with a colon. 58260786Sps 58360786Sps -M or --LONG-PROMPT 584170256Sdelphij Causes [4mless[24m to prompt even more verbosely than [4mmore.[0m 58560786Sps 58660786Sps -n or --line-numbers 587161475Sdelphij Suppresses line numbers. The default (to use line numbers) may 588170256Sdelphij cause [4mless[24m to run more slowly in some cases, especially with a 589161475Sdelphij very large input file. Suppressing line numbers with the -n 590161475Sdelphij option will avoid this problem. Using line numbers means: the 591161475Sdelphij line number will be displayed in the verbose prompt and in the = 592161475Sdelphij command, and the v command will pass the current line number to 593161475Sdelphij the editor (see also the discussion of LESSEDIT in PROMPTS 594161475Sdelphij below). 59560786Sps 596128345Stjr -N or --LINE-NUMBERS 597161475Sdelphij Causes a line number to be displayed at the beginning of each 598161475Sdelphij line in the display. 59960786Sps 600170256Sdelphij -o[4mfilename[24m or --log-file=[4mfilename[0m 601170256Sdelphij Causes [4mless[24m to copy its input to the named file as it is being 602161475Sdelphij viewed. This applies only when the input file is a pipe, not an 603170256Sdelphij ordinary file. If the file already exists, [4mless[24m will ask for 604161475Sdelphij confirmation before overwriting it. 60560786Sps 606170256Sdelphij -O[4mfilename[24m or --LOG-FILE=[4mfilename[0m 607161475Sdelphij The -O option is like -o, but it will overwrite an existing file 608161475Sdelphij without asking for confirmation. 60960786Sps 610161475Sdelphij If no log file has been specified, the -o and -O options can be 611170256Sdelphij used from within [4mless[24m to specify a log file. Without a file 612161475Sdelphij name, they will simply report the name of the log file. The "s" 613170256Sdelphij command is equivalent to specifying -o from within [4mless.[0m 61463128Sps 615170256Sdelphij -p[4mpattern[24m or --pattern=[4mpattern[0m 616161475Sdelphij The -p option on the command line is equivalent to specifying 617170256Sdelphij +/[4mpattern[24m; that is, it tells [4mless[24m to start at the first occur- 618170256Sdelphij rence of [4mpattern[24m in the file. 61963128Sps 620170256Sdelphij -P[4mprompt[24m or --prompt=[4mprompt[0m 621161475Sdelphij Provides a way to tailor the three prompt styles to your own 622161475Sdelphij preference. This option would normally be put in the LESS envi- 623170256Sdelphij ronment variable, rather than being typed in with each [4mless[24m com- 624161475Sdelphij mand. Such an option must either be the last option in the LESS 625161475Sdelphij variable, or be terminated by a dollar sign. -Ps followed by a 626161475Sdelphij string changes the default (short) prompt to that string. -Pm 627161475Sdelphij changes the medium (-m) prompt. -PM changes the long (-M) 628161475Sdelphij prompt. -Ph changes the prompt for the help screen. -P= 629161475Sdelphij changes the message printed by the = command. -Pw changes the 630161475Sdelphij message printed while waiting for data (in the F command). All 631161475Sdelphij prompt strings consist of a sequence of letters and special 632161475Sdelphij escape sequences. See the section on PROMPTS for more details. 63360786Sps 63460786Sps -q or --quiet or --silent 635161475Sdelphij Causes moderately "quiet" operation: the terminal bell is not 636161475Sdelphij rung if an attempt is made to scroll past the end of the file or 637161475Sdelphij before the beginning of the file. If the terminal has a "visual 638161475Sdelphij bell", it is used instead. The bell will be rung on certain 639161475Sdelphij other errors, such as typing an invalid character. The default 640161475Sdelphij is to ring the terminal bell in all such cases. 64160786Sps 642128345Stjr -Q or --QUIET or --SILENT 643161475Sdelphij Causes totally "quiet" operation: the terminal bell is never 644161475Sdelphij rung. 645128345Stjr 646128345Stjr -r or --raw-control-chars 647161475Sdelphij Causes "raw" control characters to be displayed. The default is 648161475Sdelphij to display control characters using the caret notation; for 649161475Sdelphij example, a control-A (octal 001) is displayed as "^A". Warning: 650170256Sdelphij when the -r option is used, [4mless[24m cannot keep track of the actual 651161475Sdelphij appearance of the screen (since this depends on how the screen 652161475Sdelphij responds to each type of control character). Thus, various dis- 653161475Sdelphij play problems may result, such as long lines being split in the 654161475Sdelphij wrong place. 65560786Sps 65663128Sps -R or --RAW-CONTROL-CHARS 657161475Sdelphij Like -r, but only ANSI "color" escape sequences are output in 658161475Sdelphij "raw" form. Unlike -r, the screen appearance is maintained cor- 659161475Sdelphij rectly in most cases. ANSI "color" escape sequences are 660161475Sdelphij sequences of the form: 66163128Sps 66263128Sps ESC [ ... m 66363128Sps 664161475Sdelphij where the "..." is zero or more color specification characters 665161475Sdelphij For the purpose of keeping track of screen appearance, ANSI 666161475Sdelphij color escape sequences are assumed to not move the cursor. You 667170256Sdelphij can make [4mless[24m think that characters other than "m" can end ANSI 668161475Sdelphij color escape sequences by setting the environment variable 669161475Sdelphij LESSANSIENDCHARS to the list of characters which can end a color 670170256Sdelphij escape sequence. And you can make [4mless[24m think that characters 671161475Sdelphij other than the standard ones may appear between the ESC and the 672161475Sdelphij m by setting the environment variable LESSANSIMIDCHARS to the 673161475Sdelphij list of characters which can appear. 67460786Sps 67560786Sps -s or --squeeze-blank-lines 676161475Sdelphij Causes consecutive blank lines to be squeezed into a single 677170256Sdelphij blank line. This is useful when viewing [4mnroff[24m output. 67860786Sps 67960786Sps -S or --chop-long-lines 680161475Sdelphij Causes lines longer than the screen width to be chopped rather 681161475Sdelphij than folded. That is, the portion of a long line that does not 682161475Sdelphij fit in the screen width is not shown. The default is to fold 683161475Sdelphij long lines; that is, display the remainder on the next line. 68460786Sps 685170256Sdelphij -t[4mtag[24m or --tag=[4mtag[0m 686161475Sdelphij The -t option, followed immediately by a TAG, will edit the file 687161475Sdelphij containing that tag. For this to work, tag information must be 688161475Sdelphij available; for example, there may be a file in the current 689170256Sdelphij directory called "tags", which was previously built by [4mctags[24m (1) 690161475Sdelphij or an equivalent command. If the environment variable LESSGLOB- 691161475Sdelphij ALTAGS is set, it is taken to be the name of a command compati- 692170256Sdelphij ble with [4mglobal[24m (1), and that command is executed to find the 693161475Sdelphij tag. (See http://www.gnu.org/software/global/global.html). The 694170256Sdelphij -t option may also be specified from within [4mless[24m (using the - 695161475Sdelphij command) as a way of examining a new file. The command ":t" is 696170256Sdelphij equivalent to specifying -t from within [4mless.[0m 69760786Sps 698170256Sdelphij -T[4mtagsfile[24m or --tag-file=[4mtagsfile[0m 69989019Sps Specifies a tags file to be used instead of "tags". 70060786Sps 70189019Sps -u or --underline-special 702161475Sdelphij Causes backspaces and carriage returns to be treated as print- 703161475Sdelphij able characters; that is, they are sent to the terminal when 704161475Sdelphij they appear in the input. 70560786Sps 70689019Sps -U or --UNDERLINE-SPECIAL 707161475Sdelphij Causes backspaces, tabs and carriage returns to be treated as 708161475Sdelphij control characters; that is, they are handled as specified by 709161475Sdelphij the -r option. 71060786Sps 711161475Sdelphij By default, if neither -u nor -U is given, backspaces which 712161475Sdelphij appear adjacent to an underscore character are treated spe- 713161475Sdelphij cially: the underlined text is displayed using the terminal's 714161475Sdelphij hardware underlining capability. Also, backspaces which appear 715161475Sdelphij between two identical characters are treated specially: the 716161475Sdelphij overstruck text is printed using the terminal's hardware bold- 717161475Sdelphij face capability. Other backspaces are deleted, along with the 718161475Sdelphij preceding character. Carriage returns immediately followed by a 719161475Sdelphij newline are deleted. other carriage returns are handled as 720161475Sdelphij specified by the -r option. Text which is overstruck or under- 721161475Sdelphij lined can be searched for if neither -u nor -U is in effect. 72260786Sps 72360786Sps -V or --version 724170256Sdelphij Displays the version number of [4mless.[0m 72560786Sps 72660786Sps -w or --hilite-unread 727161475Sdelphij Temporarily highlights the first "new" line after a forward 728161475Sdelphij movement of a full page. The first "new" line is the line imme- 729161475Sdelphij diately following the line previously at the bottom of the 730161475Sdelphij screen. Also highlights the target line after a g or p command. 731161475Sdelphij The highlight is removed at the next command which causes move- 732161475Sdelphij ment. The entire line is highlighted, unless the -J option is 733161475Sdelphij in effect, in which case only the status column is highlighted. 73460786Sps 73560786Sps -W or --HILITE-UNREAD 736161475Sdelphij Like -w, but temporarily highlights the first new line after any 737161475Sdelphij forward movement command larger than one line. 73860786Sps 739170256Sdelphij -x[4mn[24m,... or --tabs=[4mn[24m,... 740170256Sdelphij Sets tab stops. If only one [4mn[24m is specified, tab stops are set 741170256Sdelphij at multiples of [4mn[24m. If multiple values separated by commas are 742170256Sdelphij specified, tab stops are set at those positions, and then 743170256Sdelphij continue with the same spacing as the last two. For example, 744170256Sdelphij [4m-x9,17[24m will set tabs at positions 9, 17, 25, 33, etc. The 745170256Sdelphij default for [4mn[24m is 8. 74660786Sps 74789019Sps -X or --no-init 748161475Sdelphij Disables sending the termcap initialization and deinitialization 749161475Sdelphij strings to the terminal. This is sometimes desirable if the 750161475Sdelphij deinitialization string does something unnecessary, like clear- 751161475Sdelphij ing the screen. 75260786Sps 75389019Sps --no-keypad 754161475Sdelphij Disables sending the keypad initialization and deinitialization 755161475Sdelphij strings to the terminal. This is sometimes useful if the keypad 756161475Sdelphij strings make the numeric keypad behave in an undesirable manner. 75760786Sps 758170256Sdelphij -y[4mn[24m or --max-forw-scroll=[4mn[0m 759161475Sdelphij Specifies a maximum number of lines to scroll forward. If it is 760170256Sdelphij necessary to scroll forward more than [4mn[24m lines, the screen is 761161475Sdelphij repainted instead. The -c or -C option may be used to repaint 762161475Sdelphij from the top of the screen if desired. By default, any forward 76389019Sps movement causes scrolling. 76460786Sps 765170256Sdelphij -[z][4mn[24m or --window=[4mn[0m 766170256Sdelphij Changes the default scrolling window size to [4mn[24m lines. The 767161475Sdelphij default is one screenful. The z and w commands can also be used 768161475Sdelphij to change the window size. The "z" may be omitted for compati- 769170256Sdelphij bility with some versions of [4mmore.[24m If the number [4mn[24m is negative, 770170256Sdelphij it indicates [4mn[24m lines less than the current screen size. For 771170256Sdelphij example, if the screen is 24 lines, [4m-z-4[24m sets the scrolling win- 772170256Sdelphij dow to 20 lines. If the screen is resized to 40 lines, the 773170256Sdelphij scrolling window automatically changes to 36 lines. 77463128Sps 775170256Sdelphij -[4m"cc[24m or --quotes=[4mcc[0m 776161475Sdelphij Changes the filename quoting character. This may be necessary 777161475Sdelphij if you are trying to name a file which contains both spaces and 778161475Sdelphij quote characters. Followed by a single character, this changes 779161475Sdelphij the quote character to that character. Filenames containing a 780161475Sdelphij space should then be surrounded by that character rather than by 781161475Sdelphij double quotes. Followed by two characters, changes the open 782161475Sdelphij quote to the first character, and the close quote to the second 783161475Sdelphij character. Filenames containing a space should then be preceded 784161475Sdelphij by the open quote character and followed by the close quote 785161475Sdelphij character. Note that even after the quote characters are 786161475Sdelphij changed, this option remains -" (a dash followed by a double 787161475Sdelphij quote). 78860786Sps 789128345Stjr -~ or --tilde 790161475Sdelphij Normally lines after end of file are displayed as a single tilde 791161475Sdelphij (~). This option causes lines after end of file to be displayed 792161475Sdelphij as blank lines. 79360786Sps 79463128Sps -# or --shift 795161475Sdelphij Specifies the default number of positions to scroll horizontally 796161475Sdelphij in the RIGHTARROW and LEFTARROW commands. If the number speci- 797161475Sdelphij fied is zero, it sets the default number of positions to one 798161475Sdelphij half of the screen width. 79963128Sps 800161475Sdelphij -- A command line argument of "--" marks the end of option argu- 801161475Sdelphij ments. Any arguments following this are interpreted as file- 802161475Sdelphij names. This can be useful when viewing a file whose name begins 803161475Sdelphij with a "-" or "+". 80460786Sps 805170256Sdelphij + If a command line option begins with [1m+[22m, the remainder of that 806170256Sdelphij option is taken to be an initial command to [4mless.[24m For example, 807170256Sdelphij +G tells [4mless[24m to start at the end of the file rather than the 808161475Sdelphij beginning, and +/xyz tells it to start at the first occurrence 809161475Sdelphij of "xyz" in the file. As a special case, +<number> acts like 810161475Sdelphij +<number>g; that is, it starts the display at the specified line 811161475Sdelphij number (however, see the caveat under the "g" command above). 812161475Sdelphij If the option starts with ++, the initial command applies to 813161475Sdelphij every file being viewed, not just the first one. The + command 814161475Sdelphij described previously may also be used to set (or change) an ini- 815161475Sdelphij tial command for every file. 81660786Sps 81760786Sps 818170256Sdelphij[1mLINE EDITING[0m 819161475Sdelphij When entering command line at the bottom of the screen (for example, a 820170256Sdelphij filename for the :e command, or the pattern for a search command), cer- 821170256Sdelphij tain keys can be used to manipulate the command line. Most commands 822161475Sdelphij have an alternate form in [ brackets ] which can be used if a key does 823161475Sdelphij not exist on a particular keyboard. (The bracketed forms do not work 824161475Sdelphij in the MS-DOS version.) Any of these special keys may be entered lit- 825161475Sdelphij erally by preceding it with the "literal" character, either ^V or ^A. 826161475Sdelphij A backslash itself may also be entered literally by entering two back- 827161475Sdelphij slashes. 82860786Sps 82963128Sps LEFTARROW [ ESC-h ] 83063128Sps Move the cursor one space to the left. 83160786Sps 832128345Stjr RIGHTARROW [ ESC-l ] 833128345Stjr Move the cursor one space to the right. 83489019Sps 835128345Stjr ^LEFTARROW [ ESC-b or ESC-LEFTARROW ] 836161475Sdelphij (That is, CONTROL and LEFTARROW simultaneously.) Move the cur- 837161475Sdelphij sor one word to the left. 83889019Sps 839128345Stjr ^RIGHTARROW [ ESC-w or ESC-RIGHTARROW ] 840161475Sdelphij (That is, CONTROL and RIGHTARROW simultaneously.) Move the cur- 841161475Sdelphij sor one word to the right. 84260786Sps 84360786Sps HOME [ ESC-0 ] 84460786Sps Move the cursor to the beginning of the line. 84560786Sps 84660786Sps END [ ESC-$ ] 84760786Sps Move the cursor to the end of the line. 84860786Sps 84960786Sps BACKSPACE 850161475Sdelphij Delete the character to the left of the cursor, or cancel the 851161475Sdelphij command if the command line is empty. 85260786Sps 85360786Sps DELETE or [ ESC-x ] 85460786Sps Delete the character under the cursor. 85560786Sps 85660786Sps ^BACKSPACE [ ESC-BACKSPACE ] 857161475Sdelphij (That is, CONTROL and BACKSPACE simultaneously.) Delete the 858161475Sdelphij word to the left of the cursor. 85960786Sps 86060786Sps ^DELETE [ ESC-X or ESC-DELETE ] 861161475Sdelphij (That is, CONTROL and DELETE simultaneously.) Delete the word 862161475Sdelphij under the cursor. 86360786Sps 86463128Sps UPARROW [ ESC-k ] 86563128Sps Retrieve the previous command line. 86660786Sps 86763128Sps DOWNARROW [ ESC-j ] 86863128Sps Retrieve the next command line. 86960786Sps 870161475Sdelphij TAB Complete the partial filename to the left of the cursor. If it 871161475Sdelphij matches more than one filename, the first match is entered into 872161475Sdelphij the command line. Repeated TABs will cycle thru the other 873161475Sdelphij matching filenames. If the completed filename is a directory, a 874161475Sdelphij "/" is appended to the filename. (On MS-DOS systems, a "\" is 875161475Sdelphij appended.) The environment variable LESSSEPARATOR can be used 876161475Sdelphij to specify a different character to append to a directory name. 87760786Sps 87863128Sps BACKTAB [ ESC-TAB ] 879161475Sdelphij Like, TAB, but cycles in the reverse direction thru the matching 880161475Sdelphij filenames. 88160786Sps 882161475Sdelphij ^L Complete the partial filename to the left of the cursor. If it 883161475Sdelphij matches more than one filename, all matches are entered into the 884161475Sdelphij command line (if they fit). 88560786Sps 886128345Stjr ^U (Unix and OS/2) or ESC (MS-DOS) 887161475Sdelphij Delete the entire command line, or cancel the command if the 888161475Sdelphij command line is empty. If you have changed your line-kill char- 889161475Sdelphij acter in Unix to something other than ^U, that character is used 890161475Sdelphij instead of ^U. 891128345Stjr 892128345Stjr 893170256Sdelphij[1mKEY BINDINGS[0m 894170256Sdelphij You may define your own [4mless[24m commands by using the program [4mlesskey[24m (1) 895161475Sdelphij to create a lesskey file. This file specifies a set of command keys 896170256Sdelphij and an action associated with each key. You may also use [4mlesskey[24m to 897161475Sdelphij change the line-editing keys (see LINE EDITING), and to set environment 898170256Sdelphij variables. If the environment variable LESSKEY is set, [4mless[24m uses that 899170256Sdelphij as the name of the lesskey file. Otherwise, [4mless[24m looks in a standard 900170256Sdelphij place for the lesskey file: On Unix systems, [4mless[24m looks for a lesskey 901170256Sdelphij file called "$HOME/.less". On MS-DOS and Windows systems, [4mless[24m looks 902161475Sdelphij for a lesskey file called "$HOME/_less", and if it is not found there, 903161475Sdelphij then looks for a lesskey file called "_less" in any directory specified 904170256Sdelphij in the PATH environment variable. On OS/2 systems, [4mless[24m looks for a 905161475Sdelphij lesskey file called "$HOME/less.ini", and if it is not found, then 906161475Sdelphij looks for a lesskey file called "less.ini" in any directory specified 907161475Sdelphij in the INIT environment variable, and if it not found there, then looks 908161475Sdelphij for a lesskey file called "less.ini" in any directory specified in the 909170256Sdelphij PATH environment variable. See the [4mlesskey[24m manual page for more 910161475Sdelphij details. 91160786Sps 912161475Sdelphij A system-wide lesskey file may also be set up to provide key bindings. 913161475Sdelphij If a key is defined in both a local lesskey file and in the system-wide 914161475Sdelphij file, key bindings in the local file take precedence over those in the 915161475Sdelphij system-wide file. If the environment variable LESSKEY_SYSTEM is set, 916170256Sdelphij [4mless[24m uses that as the name of the system-wide lesskey file. Otherwise, 917170256Sdelphij [4mless[24m looks in a standard place for the system-wide lesskey file: On 918161475Sdelphij Unix systems, the system-wide lesskey file is /usr/local/etc/sysless. 919170256Sdelphij (However, if [4mless[24m was built with a different sysconf directory than 920161475Sdelphij /usr/local/etc, that directory is where the sysless file is found.) On 921161475Sdelphij MS-DOS and Windows systems, the system-wide lesskey file is c:\_sys- 922161475Sdelphij less. On OS/2 systems, the system-wide lesskey file is c:\sysless.ini. 92360786Sps 92460786Sps 925170256Sdelphij[1mINPUT PREPROCESSOR[0m 926170256Sdelphij You may define an "input preprocessor" for [4mless.[24m Before [4mless[24m opens a 927161475Sdelphij file, it first gives your input preprocessor a chance to modify the way 928161475Sdelphij the contents of the file are displayed. An input preprocessor is sim- 929161475Sdelphij ply an executable program (or shell script), which writes the contents 930161475Sdelphij of the file to a different file, called the replacement file. The con- 931161475Sdelphij tents of the replacement file are then displayed in place of the con- 932161475Sdelphij tents of the original file. However, it will appear to the user as if 933170256Sdelphij the original file is opened; that is, [4mless[24m will display the original 934161475Sdelphij filename as the name of the current file. 93560786Sps 936161475Sdelphij An input preprocessor receives one command line argument, the original 937161475Sdelphij filename, as entered by the user. It should create the replacement 938161475Sdelphij file, and when finished, print the name of the replacement file to its 939161475Sdelphij standard output. If the input preprocessor does not output a replace- 940170256Sdelphij ment filename, [4mless[24m uses the original file, as normal. The input pre- 941161475Sdelphij processor is not called when viewing standard input. To set up an 942161475Sdelphij input preprocessor, set the LESSOPEN environment variable to a command 943161475Sdelphij line which will invoke your input preprocessor. This command line 944161475Sdelphij should include one occurrence of the string "%s", which will be 945161475Sdelphij replaced by the filename when the input preprocessor command is 94689019Sps invoked. 94789019Sps 948170256Sdelphij When [4mless[24m closes a file opened in such a way, it will call another pro- 949161475Sdelphij gram, called the input postprocessor, which may perform any desired 950161475Sdelphij clean-up action (such as deleting the replacement file created by 951161475Sdelphij LESSOPEN). This program receives two command line arguments, the orig- 952161475Sdelphij inal filename as entered by the user, and the name of the replacement 953161475Sdelphij file. To set up an input postprocessor, set the LESSCLOSE environment 954161475Sdelphij variable to a command line which will invoke your input postprocessor. 955161475Sdelphij It may include two occurrences of the string "%s"; the first is 956161475Sdelphij replaced with the original name of the file and the second with the 957161475Sdelphij name of the replacement file, which was output by LESSOPEN. 95860786Sps 959161475Sdelphij For example, on many Unix systems, these two scripts will allow you to 960170256Sdelphij keep files in compressed format, but still let [4mless[24m view them directly: 96160786Sps 96260786Sps lessopen.sh: 96360786Sps #! /bin/sh 96460786Sps case "$1" in 965161475Sdelphij *.Z) uncompress - 96660786Sps if [ -s /tmp/less.$$ ]; then 96760786Sps echo /tmp/less.$$ 96860786Sps else 96960786Sps rm -f /tmp/less.$$ 97060786Sps fi 97160786Sps ;; 97260786Sps esac 97360786Sps 97460786Sps lessclose.sh: 97560786Sps #! /bin/sh 97660786Sps rm $2 97760786Sps 978161475Sdelphij To use these scripts, put them both where they can be executed and set 979161475Sdelphij LESSOPEN="lessopen.sh %s", and LESSCLOSE="lessclose.sh %s %s". More 980161475Sdelphij complex LESSOPEN and LESSCLOSE scripts may be written to accept other 981161475Sdelphij types of compressed files, and so on. 98260786Sps 983161475Sdelphij It is also possible to set up an input preprocessor to pipe the file 984170256Sdelphij data directly to [4mless,[24m rather than putting the data into a replacement 985161475Sdelphij file. This avoids the need to decompress the entire file before start- 986161475Sdelphij ing to view it. An input preprocessor that works this way is called an 987161475Sdelphij input pipe. An input pipe, instead of writing the name of a replace- 988161475Sdelphij ment file on its standard output, writes the entire contents of the 989161475Sdelphij replacement file on its standard output. If the input pipe does not 990161475Sdelphij write any characters on its standard output, then there is no replace- 991170256Sdelphij ment file and [4mless[24m uses the original file, as normal. To use an input 992161475Sdelphij pipe, make the first character in the LESSOPEN environment variable a 993161475Sdelphij vertical bar (|) to signify that the input preprocessor is an input 994161475Sdelphij pipe. 99589019Sps 996161475Sdelphij For example, on many Unix systems, this script will work like the pre- 997161475Sdelphij vious example scripts: 99889019Sps 99960786Sps lesspipe.sh: 100060786Sps #! /bin/sh 100160786Sps case "$1" in 100260786Sps *.Z) uncompress -c $1 2>/dev/null 100360786Sps ;; 100460786Sps esac 100560786Sps 1006161475Sdelphij To use this script, put it where it can be executed and set 1007161475Sdelphij LESSOPEN="|lesspipe.sh %s". When an input pipe is used, a LESSCLOSE 1008161475Sdelphij postprocessor can be used, but it is usually not necessary since there 1009161475Sdelphij is no replacement file to clean up. In this case, the replacement file 1010161475Sdelphij name passed to the LESSCLOSE postprocessor is "-". 101160786Sps 101260786Sps 1013170256Sdelphij[1mNATIONAL CHARACTER SETS[0m 101460786Sps There are three types of characters in the input file: 101560786Sps 101660786Sps normal characters 101760786Sps can be displayed directly to the screen. 101860786Sps 101960786Sps control characters 1020161475Sdelphij should not be displayed directly, but are expected to be found 1021161475Sdelphij in ordinary text files (such as backspace and tab). 102260786Sps 102360786Sps binary characters 1024161475Sdelphij should not be displayed directly and are not expected to be 1025161475Sdelphij found in text files. 102660786Sps 1027161475Sdelphij A "character set" is simply a description of which characters are to be 1028161475Sdelphij considered normal, control, and binary. The LESSCHARSET environment 1029161475Sdelphij variable may be used to select a character set. Possible values for 1030161475Sdelphij LESSCHARSET are: 103160786Sps 1032161475Sdelphij ascii BS, TAB, NL, CR, and formfeed are control characters, all chars 1033161475Sdelphij with values between 32 and 126 are normal, and all others are 1034161475Sdelphij binary. 103560786Sps 103689019Sps iso8859 1037161475Sdelphij Selects an ISO 8859 character set. This is the same as ASCII, 1038161475Sdelphij except characters between 160 and 255 are treated as normal 1039161475Sdelphij characters. 104060786Sps 104189019Sps latin1 Same as iso8859. 104260786Sps 104389019Sps latin9 Same as iso8859. 104460786Sps 104589019Sps dos Selects a character set appropriate for MS-DOS. 104660786Sps 104789019Sps ebcdic Selects an EBCDIC character set. 104860786Sps 104989019Sps IBM-1047 1050161475Sdelphij Selects an EBCDIC character set used by OS/390 Unix Services. 1051161475Sdelphij This is the EBCDIC analogue of latin1. You get similar results 1052161475Sdelphij by setting either LESSCHARSET=IBM-1047 or LC_CTYPE=en_US in your 1053161475Sdelphij environment. 105460786Sps 105589019Sps koi8-r Selects a Russian character set. 105660786Sps 1057161475Sdelphij next Selects a character set appropriate for NeXT computers. 105889019Sps 1059170256Sdelphij utf-8 Selects the UTF-8 encoding of the ISO 10646 character set. 1060170256Sdelphij UTF-8 is special in that it supports multi-byte characters in 1061170256Sdelphij the input file. It is the only character set that supports 1062170256Sdelphij multi-byte characters. 106389019Sps 1064161475Sdelphij windows 1065170256Sdelphij Selects a character set appropriate for Microsoft Windows (cp 1066161475Sdelphij 1251). 106760786Sps 1068170256Sdelphij In special cases, it may be desired to tailor [4mless[24m to use a character 1069170256Sdelphij set other than the ones definable by LESSCHARSET. In this case, the 1070161475Sdelphij environment variable LESSCHARDEF can be used to define a character set. 1071170256Sdelphij It should be set to a string where each character in the string repre- 1072170256Sdelphij sents one character in the character set. The character "." is used 1073161475Sdelphij for a normal character, "c" for control, and "b" for binary. A decimal 1074170256Sdelphij number may be used for repetition. For example, "bccc4b." would mean 1075170256Sdelphij character 0 is binary, 1, 2 and 3 are control, 4, 5, 6 and 7 are 1076161475Sdelphij binary, and 8 is normal. All characters after the last are taken to be 1077170256Sdelphij the same as the last, so characters 9 through 255 would be normal. 1078170256Sdelphij (This is an example, and does not necessarily represent any real char- 1079161475Sdelphij acter set.) 108060786Sps 1081170256Sdelphij This table shows the value of LESSCHARDEF which is equivalent to each 1082161475Sdelphij of the possible values for LESSCHARSET: 108389019Sps 1084128345Stjr ascii 8bcccbcc18b95.b 1085128345Stjr dos 8bcccbcc12bc5b95.b. 1086128345Stjr ebcdic 5bc6bcc7bcc41b.9b7.9b5.b..8b6.10b6.b9.7b 1087128345Stjr 9.8b8.17b3.3b9.7b9.8b8.6b10.b.b.b. 1088128345Stjr IBM-1047 4cbcbc3b9cbccbccbb4c6bcc5b3cbbc4bc4bccbc 1089128345Stjr 191.b 1090128345Stjr iso8859 8bcccbcc18b95.33b. 1091128345Stjr koi8-r 8bcccbcc18b95.b128. 109260786Sps latin1 8bcccbcc18b95.33b. 109360786Sps next 8bcccbcc18b95.bb125.bb 109460786Sps 1095170256Sdelphij If neither LESSCHARSET nor LESSCHARDEF is set, but any of the strings 1096170256Sdelphij "UTF-8", "UTF8", "utf-8" or "utf8" is found in the LC_ALL, LC_TYPE or 1097161475Sdelphij LANG environment variables, then the default character set is utf-8. 109860786Sps 1099170256Sdelphij If that string is not found, but your system supports the [4msetlocale[0m 1100170256Sdelphij interface, [4mless[24m will use setlocale to determine the character set. 1101170256Sdelphij setlocale is controlled by setting the LANG or LC_CTYPE environment 1102161475Sdelphij variables. 110389019Sps 1104170256Sdelphij Finally, if the [4msetlocale[24m interface is also not available, the default 1105161475Sdelphij character set is latin1. 110689019Sps 1107170256Sdelphij Control and binary characters are displayed in standout (reverse 1108161475Sdelphij video). Each such character is displayed in caret notation if possible 1109170256Sdelphij (e.g. ^A for control-A). Caret notation is used only if inverting the 1110161475Sdelphij 0100 bit results in a normal printable character. Otherwise, the char- 1111170256Sdelphij acter is displayed as a hex number in angle brackets. This format can 1112170256Sdelphij be changed by setting the LESSBINFMT environment variable. LESSBINFMT 1113161475Sdelphij may begin with a "*" and one character to select the display attribute: 1114170256Sdelphij "*k" is blinking, "*d" is bold, "*u" is underlined, "*s" is standout, 1115170256Sdelphij and "*n" is normal. If LESSBINFMT does not begin with a "*", normal 1116170256Sdelphij attribute is assumed. The remainder of LESSBINFMT is a string which 1117170256Sdelphij may include one printf-style escape sequence (a % followed by x, X, o, 1118170256Sdelphij d, etc.). For example, if LESSBINFMT is "*u[%x]", binary characters 1119170256Sdelphij are displayed in underlined hexadecimal surrounded by brackets. The 1120170256Sdelphij default if no LESSBINFMT is specified is "*s<%X>". The default if no 1121170256Sdelphij LESSBINFMT is specified is "*s<%02X>". Warning: the result of expand- 1122161475Sdelphij ing the character via LESSBINFMT must be less than 31 characters. 112360786Sps 1124161475Sdelphij When the character set is utf-8, the LESSUTFBINFMT environment variable 1125161475Sdelphij acts similarly to LESSBINFMT but it applies to Unicode code points that 1126170256Sdelphij were successfully decoded but are unsuitable for display (e.g., unas- 1127170256Sdelphij signed code points). Its default value is "<U+%04lX>". Note that 1128170256Sdelphij LESSUTFBINFMT and LESSBINFMT share their display attribute setting 1129170256Sdelphij ("*x") so specifying one will affect both; LESSUTFBINFMT is read after 1130170256Sdelphij LESSBINFMT so its setting, if any, will have priority. Problematic 1131170256Sdelphij octets in a UTF-8 file (octets of a truncated sequence, octets of a 1132170256Sdelphij complete but non-shortest form sequence, illegal octets, and stray 1133170256Sdelphij trailing octets) are displayed individually using LESSBINFMT so as to 1134161475Sdelphij facilitate diagnostic of how the UTF-8 file is ill-formed. 113560786Sps 1136161475Sdelphij 1137170256Sdelphij[1mPROMPTS[0m 1138170256Sdelphij The -P option allows you to tailor the prompt to your preference. The 1139170256Sdelphij string given to the -P option replaces the specified prompt string. 1140161475Sdelphij Certain characters in the string are interpreted specially. The prompt 1141170256Sdelphij mechanism is rather complicated to provide flexibility, but the ordi- 1142170256Sdelphij nary user need not understand the details of constructing personalized 1143161475Sdelphij prompt strings. 114460786Sps 1145170256Sdelphij A percent sign followed by a single character is expanded according to 1146161475Sdelphij what the following character is: 114760786Sps 1148170256Sdelphij %b[4mX[24m Replaced by the byte offset into the current input file. The b 1149170256Sdelphij is followed by a single character (shown as [4mX[24m above) which spec- 1150170256Sdelphij ifies the line whose byte offset is to be used. If the charac- 1151170256Sdelphij ter is a "t", the byte offset of the top line in the display is 1152161475Sdelphij used, an "m" means use the middle line, a "b" means use the bot- 1153170256Sdelphij tom line, a "B" means use the line just after the bottom line, 1154170256Sdelphij and a "j" means use the "target" line, as specified by the -j 1155161475Sdelphij option. 115660786Sps 115760786Sps %B Replaced by the size of the current input file. 115860786Sps 1159161475Sdelphij %c Replaced by the column number of the text appearing in the first 1160161475Sdelphij column of the screen. 116160786Sps 1162170256Sdelphij %d[4mX[24m Replaced by the page number of a line in the input file. The 1163170256Sdelphij line to be used is determined by the [4mX[24m, as with the %b option. 116460786Sps 1165170256Sdelphij %D Replaced by the number of pages in the input file, or equiva- 1166161475Sdelphij lently, the page number of the last line in the input file. 116760786Sps 1168170256Sdelphij %E Replaced by the name of the editor (from the VISUAL environment 1169170256Sdelphij variable, or the EDITOR environment variable if VISUAL is not 1170161475Sdelphij defined). See the discussion of the LESSEDIT feature below. 117160786Sps 117260786Sps %f Replaced by the name of the current input file. 117360786Sps 1174170256Sdelphij %i Replaced by the index of the current file in the list of input 1175161475Sdelphij files. 117660786Sps 1177170256Sdelphij %l[4mX[24m Replaced by the line number of a line in the input file. The 1178170256Sdelphij line to be used is determined by the [4mX[24m, as with the %b option. 117960786Sps 1180170256Sdelphij %L Replaced by the line number of the last line in the input file. 118160786Sps 118260786Sps %m Replaced by the total number of input files. 118360786Sps 1184170256Sdelphij %p[4mX[24m Replaced by the percent into the current input file, based on 1185170256Sdelphij byte offsets. The line used is determined by the [4mX[24m as with the 1186161475Sdelphij %b option. 118760786Sps 1188170256Sdelphij %P[4mX[24m Replaced by the percent into the current input file, based on 1189170256Sdelphij line numbers. The line used is determined by the [4mX[24m as with the 1190161475Sdelphij %b option. 119160786Sps 119289019Sps %s Same as %B. 119360786Sps 1194170256Sdelphij %t Causes any trailing spaces to be removed. Usually used at the 1195161475Sdelphij end of the string, but may appear anywhere. 119660786Sps 1197161475Sdelphij %x Replaced by the name of the next input file in the list. 119860786Sps 1199161475Sdelphij If any item is unknown (for example, the file size if input is a pipe), 1200161475Sdelphij a question mark is printed instead. 120160786Sps 1202170256Sdelphij The format of the prompt string can be changed depending on certain 1203170256Sdelphij conditions. A question mark followed by a single character acts like 1204170256Sdelphij an "IF": depending on the following character, a condition is evalu- 1205170256Sdelphij ated. If the condition is true, any characters following the question 1206170256Sdelphij mark and condition character, up to a period, are included in the 1207170256Sdelphij prompt. If the condition is false, such characters are not included. 1208170256Sdelphij A colon appearing between the question mark and the period can be used 1209161475Sdelphij to establish an "ELSE": any characters between the colon and the period 1210170256Sdelphij are included in the string if and only if the IF condition is false. 1211161475Sdelphij Condition characters (which follow a question mark) may be: 121260786Sps 1213170256Sdelphij ?a True if any characters have been included in the prompt so far. 121460786Sps 1215170256Sdelphij ?b[4mX[24m True if the byte offset of the specified line is known. 121660786Sps 121760786Sps ?B True if the size of current input file is known. 121860786Sps 1219161475Sdelphij ?c True if the text is horizontally shifted (%c is not zero). 122060786Sps 1221170256Sdelphij ?d[4mX[24m True if the page number of the specified line is known. 122260786Sps 122360786Sps ?e True if at end-of-file. 122460786Sps 1225170256Sdelphij ?f True if there is an input filename (that is, if input is not a 1226161475Sdelphij pipe). 122760786Sps 1228170256Sdelphij ?l[4mX[24m True if the line number of the specified line is known. 122963128Sps 1230161475Sdelphij ?L True if the line number of the last line in the file is known. 123163128Sps 123289019Sps ?m True if there is more than one input file. 123363128Sps 1234161475Sdelphij ?n True if this is the first prompt in a new input file. 123563128Sps 1236170256Sdelphij ?p[4mX[24m True if the percent into the current input file, based on byte 1237161475Sdelphij offsets, of the specified line is known. 123863128Sps 1239170256Sdelphij ?P[4mX[24m True if the percent into the current input file, based on line 1240161475Sdelphij numbers, of the specified line is known. 124163128Sps 1242128345Stjr ?s Same as "?B". 124360786Sps 1244170256Sdelphij ?x True if there is a next input file (that is, if the current 1245161475Sdelphij input file is not the last one). 124660786Sps 1247170256Sdelphij Any characters other than the special ones (question mark, colon, 1248170256Sdelphij period, percent, and backslash) become literally part of the prompt. 1249170256Sdelphij Any of the special characters may be included in the prompt literally 1250161475Sdelphij by preceding it with a backslash. 125160786Sps 125260786Sps Some examples: 125360786Sps 125460786Sps ?f%f:Standard input. 125560786Sps 1256170256Sdelphij This prompt prints the filename, if known; otherwise the string "Stan- 1257161475Sdelphij dard input". 125860786Sps 125960786Sps ?f%f .?ltLine %lt:?pt%pt\%:?btByte %bt:-... 126060786Sps 1261170256Sdelphij This prompt would print the filename, if known. The filename is fol- 1262170256Sdelphij lowed by the line number, if known, otherwise the percent if known, 1263170256Sdelphij otherwise the byte offset if known. Otherwise, a dash is printed. 1264170256Sdelphij Notice how each question mark has a matching period, and how the % 1265161475Sdelphij after the %pt is included literally by escaping it with a backslash. 126660786Sps 126760786Sps ?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\: %x..%t 126860786Sps 1269170256Sdelphij This prints the filename if this is the first prompt in a file, fol- 1270170256Sdelphij lowed by the "file N of N" message if there is more than one input 1271170256Sdelphij file. Then, if we are at end-of-file, the string "(END)" is printed 1272170256Sdelphij followed by the name of the next file, if there is one. Finally, any 1273161475Sdelphij trailing spaces are truncated. This is the default prompt. For refer- 1274170256Sdelphij ence, here are the defaults for the other two prompts (-m and -M 1275170256Sdelphij respectively). Each is broken into two lines here for readability 1276161475Sdelphij only. 127763128Sps 127889019Sps ?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\: %x.: 127989019Sps ?pB%pB\%:byte %bB?s/%s...%t 128063128Sps 128189019Sps ?f%f .?n?m(file %i of %m) ..?ltlines %lt-%lb?L/%L. : 128289019Sps byte %bB?s/%s. .?e(END) ?x- Next\: %x.:?pB%pB\%..%t 128363128Sps 128489019Sps And here is the default message produced by the = command: 128563128Sps 128689019Sps ?f%f .?m(file %i of %m) .?ltlines %lt-%lb?L/%L. . 1287128345Stjr byte %bB?s/%s. ?e(END) :?pB%pB\%..%t 1288128345Stjr 1289170256Sdelphij The prompt expansion features are also used for another purpose: if an 1290170256Sdelphij environment variable LESSEDIT is defined, it is used as the command to 1291170256Sdelphij be executed when the v command is invoked. The LESSEDIT string is 1292170256Sdelphij expanded in the same way as the prompt strings. The default value for 1293128345Stjr LESSEDIT is: 1294128345Stjr 129560786Sps %E ?lm+%lm. %f 129660786Sps 1297161475Sdelphij Note that this expands to the editor name, followed by a + and the line 1298170256Sdelphij number, followed by the file name. If your editor does not accept the 1299170256Sdelphij "+linenumber" syntax, or has other differences in invocation syntax, 1300161475Sdelphij the LESSEDIT variable can be changed to modify this default. 130160786Sps 130260786Sps 1303170256Sdelphij[1mSECURITY[0m 1304170256Sdelphij When the environment variable LESSSECURE is set to 1, [4mless[24m runs in a 1305161475Sdelphij "secure" mode. This means these features are disabled: 130660786Sps 130760786Sps ! the shell command 130860786Sps 130960786Sps | the pipe command 131060786Sps 131160786Sps :e the examine command. 131260786Sps 131360786Sps v the editing command 131460786Sps 131560786Sps s -o log files 131660786Sps 131760786Sps -k use of lesskey files 131860786Sps 131960786Sps -t use of tags files 132060786Sps 132160786Sps metacharacters in filenames, such as * 132260786Sps 132360786Sps filename completion (TAB, ^L) 132460786Sps 1325161475Sdelphij Less can also be compiled to be permanently in "secure" mode. 132660786Sps 132760786Sps 1328170256Sdelphij[1mCOMPATIBILITY WITH MORE[0m 1329170256Sdelphij If the environment variable LESS_IS_MORE is set to 1, or if the program 1330170256Sdelphij is invoked via a file link named "more", [4mless[24m behaves (mostly) in con- 1331170256Sdelphij formance with the POSIX "more" command specification. In this mode, 1332170256Sdelphij less behaves differently in these ways: 1333170256Sdelphij 1334170256Sdelphij The -e option works differently. If the -e option is not set, [4mless[0m 1335170256Sdelphij behaves as if the -E option were set. If the -e option is set, [4mless[0m 1336170256Sdelphij behaves as if the -e and -F options were set. 1337170256Sdelphij 1338170256Sdelphij The -m option works differently. If the -m option is not set, the 1339170256Sdelphij medium prompt is used, and it is prefixed with the string "--More--". 1340170256Sdelphij If the -m option is set, the short prompt is used. 1341170256Sdelphij 1342170256Sdelphij The -n option acts like the -z option. The normal behavior of the -n 1343170256Sdelphij option is unavailable in this mode. 1344170256Sdelphij 1345170256Sdelphij The parameter to the -p option is taken to be a [4mless[24m command rather 1346170256Sdelphij than a search pattern. 1347170256Sdelphij 1348170256Sdelphij The LESS environment variable is ignored, and the MORE environment 1349170256Sdelphij variable is used in its place. 1350170256Sdelphij 1351170256Sdelphij 1352170256Sdelphij[1mENVIRONMENT VARIABLES[0m 1353161475Sdelphij Environment variables may be specified either in the system environment 1354170256Sdelphij as usual, or in a [4mlesskey[24m (1) file. If environment variables are 1355170256Sdelphij defined in more than one place, variables defined in a local lesskey 1356170256Sdelphij file take precedence over variables defined in the system environment, 1357161475Sdelphij which take precedence over variables defined in the system-wide lesskey 1358161475Sdelphij file. 135960786Sps 1360128345Stjr COLUMNS 1361161475Sdelphij Sets the number of columns on the screen. Takes precedence over 1362170256Sdelphij the number of columns specified by the TERM variable. (But if 1363161475Sdelphij you have a windowing system which supports TIOCGWINSZ or 1364170256Sdelphij WIOCGETD, the window system's idea of the screen size takes 1365161475Sdelphij precedence over the LINES and COLUMNS environment variables.) 1366128345Stjr 136763128Sps EDITOR The name of the editor (used for the v command). 136860786Sps 1369170256Sdelphij HOME Name of the user's home directory (used to find a lesskey file 1370161475Sdelphij on Unix and OS/2 systems). 137160786Sps 137260786Sps HOMEDRIVE, HOMEPATH 1373170256Sdelphij Concatenation of the HOMEDRIVE and HOMEPATH environment vari- 1374161475Sdelphij ables is the name of the user's home directory if the HOME vari- 1375161475Sdelphij able is not set (only in the Windows version). 137660786Sps 1377170256Sdelphij INIT Name of the user's init directory (used to find a lesskey file 1378161475Sdelphij on OS/2 systems). 137960786Sps 138060786Sps LANG Language for determining the character set. 138160786Sps 138260786Sps LC_CTYPE 138360786Sps Language for determining the character set. 138460786Sps 1385170256Sdelphij LESS Options which are passed to [4mless[24m automatically. 138660786Sps 138760786Sps LESSANSIENDCHARS 1388170256Sdelphij Characters which may end an ANSI color escape sequence (default 1389161475Sdelphij "m"). 139060786Sps 1391161475Sdelphij LESSANSIMIDCHARS 1392170256Sdelphij Characters which may appear between the ESC character and the 1393170256Sdelphij end character in an ANSI color escape sequence (default 1394161475Sdelphij "0123456789;[?!"'#%()*+ ". 1395161475Sdelphij 139660786Sps LESSBINFMT 1397161475Sdelphij Format for displaying non-printable, non-control characters. 139860786Sps 139960786Sps LESSCHARDEF 140060786Sps Defines a character set. 140160786Sps 140289019Sps LESSCHARSET 140389019Sps Selects a predefined character set. 140463128Sps 140589019Sps LESSCLOSE 1406161475Sdelphij Command line to invoke the (optional) input-postprocessor. 140763128Sps 140889019Sps LESSECHO 1409161475Sdelphij Name of the lessecho program (default "lessecho"). The lessecho 1410170256Sdelphij program is needed to expand metacharacters, such as * and ?, in 1411161475Sdelphij filenames on Unix systems. 141263128Sps 1413161475Sdelphij LESSEDIT 1414170256Sdelphij Editor prototype string (used for the v command). See discus- 1415161475Sdelphij sion under PROMPTS. 141663128Sps 1417161475Sdelphij LESSGLOBALTAGS 1418170256Sdelphij Name of the command used by the -t option to find global tags. 1419170256Sdelphij Normally should be set to "global" if your system has the [4mglobal[0m 1420161475Sdelphij (1) command. If not set, global tags are not used. 142163128Sps 1422161475Sdelphij LESSHISTFILE 1423170256Sdelphij Name of the history file used to remember search commands and 1424170256Sdelphij shell commands between invocations of [4mless.[24m If set to "-" or 1425170256Sdelphij "/dev/null", a history file is not used. The default is 1426170256Sdelphij "$HOME/.lesshst" on Unix systems, "$HOME/_lesshst" on DOS and 1427170256Sdelphij Windows systems, or "$HOME/lesshst.ini" or "$INIT/lesshst.ini" 1428170256Sdelphij on OS/2 systems. 142963128Sps 1430161475Sdelphij LESSHISTSIZE 1431161475Sdelphij The maximum number of commands to save in the history file. The 1432161475Sdelphij default is 100. 143363128Sps 143460786Sps LESSKEY 143560786Sps Name of the default lesskey(1) file. 143660786Sps 143760786Sps LESSKEY_SYSTEM 143860786Sps Name of the default system-wide lesskey(1) file. 143960786Sps 144060786Sps LESSMETACHARS 1441161475Sdelphij List of characters which are considered "metacharacters" by the 1442161475Sdelphij shell. 144360786Sps 144460786Sps LESSMETAESCAPE 1445161475Sdelphij Prefix which less will add before each metacharacter in a com- 1446161475Sdelphij mand sent to the shell. If LESSMETAESCAPE is an empty string, 1447161475Sdelphij commands containing metacharacters will not be passed to the 1448161475Sdelphij shell. 144960786Sps 145060786Sps LESSOPEN 1451161475Sdelphij Command line to invoke the (optional) input-preprocessor. 145260786Sps 145360786Sps LESSSECURE 1454161475Sdelphij Runs less in "secure" mode. See discussion under SECURITY. 145560786Sps 145660786Sps LESSSEPARATOR 1457161475Sdelphij String to be appended to a directory name in filename comple- 1458161475Sdelphij tion. 145960786Sps 1460161475Sdelphij LESSUTFBINFMT 1461161475Sdelphij Format for displaying non-printable Unicode code points. 146260786Sps 1463170256Sdelphij LESS_IS_MORE 1464170256Sdelphij Emulate the [4mmore[24m (1) command. 1465170256Sdelphij 1466161475Sdelphij LINES Sets the number of lines on the screen. Takes precedence over 1467161475Sdelphij the number of lines specified by the TERM variable. (But if you 1468161475Sdelphij have a windowing system which supports TIOCGWINSZ or WIOCGETD, 1469161475Sdelphij the window system's idea of the screen size takes precedence 1470161475Sdelphij over the LINES and COLUMNS environment variables.) 147163128Sps 1472161475Sdelphij PATH User's search path (used to find a lesskey file on MS-DOS and 1473161475Sdelphij OS/2 systems). 147463128Sps 1475161475Sdelphij SHELL The shell used to execute the ! command, as well as to expand 1476161475Sdelphij filenames. 1477161475Sdelphij 1478170256Sdelphij TERM The type of terminal on which [4mless[24m is being run. 147963128Sps 1480128345Stjr VISUAL The name of the editor (used for the v command). 148160786Sps 148260786Sps 1483170256Sdelphij[1mSEE ALSO[0m 1484128345Stjr lesskey(1) 148560786Sps 148660786Sps 1487170256Sdelphij[1mWARNINGS[0m 1488161475Sdelphij The = command and prompts (unless changed by -P) report the line num- 1489161475Sdelphij bers of the lines at the top and bottom of the screen, but the byte and 1490161475Sdelphij percent of the line after the one at the bottom of the screen. 149160786Sps 1492161475Sdelphij On certain older terminals (the so-called "magic cookie" terminals), 1493161475Sdelphij search highlighting will cause an erroneous display. On such termi- 1494161475Sdelphij nals, search highlighting is disabled by default to avoid possible 1495161475Sdelphij problems. 149660786Sps 1497170256Sdelphij When searching in a binary file, text which follows a null byte may not 1498170256Sdelphij be found. This problem does not occur when searching with regular 1499170256Sdelphij expressions turned off via ^R, and also does not occur when [4mless[24m is 1500170256Sdelphij compiled to use the PCRE regular expression library. 1501170256Sdelphij 1502161475Sdelphij In certain cases, when search highlighting is enabled and a search pat- 1503170256Sdelphij tern begins with a ^, more text than the matching string may be high- 1504161475Sdelphij lighted. (This problem does not occur when less is compiled to use the 1505161475Sdelphij POSIX regular expression package.) 150660786Sps 1507170256Sdelphij On some systems, [4msetlocale[24m claims that ASCII characters 0 thru 31 are 1508170256Sdelphij control characters rather than binary characters. This causes [4mless[24m to 1509161475Sdelphij treat some binary files as ordinary, non-binary files. To workaround 1510161475Sdelphij this problem, set the environment variable LESSCHARSET to "ascii" (or 151163128Sps whatever character set is appropriate). 151260786Sps 1513161475Sdelphij This manual is too long. 151460786Sps 1515170256Sdelphij See http://www.greenwoodsoftware.com/less for the latest list of known 1516170256Sdelphij bugs in less. 151760786Sps 1518161475Sdelphij 1519170256Sdelphij[1mCOPYRIGHT[0m 1520170256Sdelphij Copyright (C) 1984-2007 Mark Nudelman 152160786Sps 1522161475Sdelphij less is part of the GNU project and is free software. You can redis- 1523161475Sdelphij tribute it and/or modify it under the terms of either (1) the GNU Gen- 1524161475Sdelphij eral Public License as published by the Free Software Foundation; or 1525161475Sdelphij (2) the Less License. See the file README in the less distribution for 1526161475Sdelphij more details regarding redistribution. You should have received a copy 1527161475Sdelphij of the GNU General Public License along with the source for less; see 1528161475Sdelphij the file COPYING. If not, write to the Free Software Foundation, 59 1529161475Sdelphij Temple Place, Suite 330, Boston, MA 02111-1307, USA. You should also 1530161475Sdelphij have received a copy of the Less License; see the file LICENSE. 153160786Sps 1532161475Sdelphij less is distributed in the hope that it will be useful, but WITHOUT ANY 1533161475Sdelphij WARRANTY; without even the implied warranty of MERCHANTABILITY or FIT- 1534161475Sdelphij NESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 1535161475Sdelphij more details. 153660786Sps 153760786Sps 1538170256Sdelphij[1mAUTHOR[0m 153989019Sps Mark Nudelman <markn@greenwoodsoftware.com> 1540170256Sdelphij Send bug reports or comments to the above address or to 1541170256Sdelphij bug-less@gnu.org. 1542170256Sdelphij For more information, see the less homepage at 1543170256Sdelphij http://www.greenwoodsoftware.com/less. 154460786Sps 154560786Sps 154660786Sps 1547170256Sdelphij Version 403: 25 May 2007 LESS(1) 1548